<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>北极光之夜。</title>
  <style>
    *{
      padding: 0;
      margin: 0;
      box-sizing: border-box;
    }
    body{
      height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      background-color: rgb(0, 0, 0);
    }
    h1{
      font-family: 'fangsong';
      font-size: 6em;
      color: transparent;
    }
    span{
      display: table-cell;
      animation: san 3s linear infinite;
    }
    h1 span:nth-child(1){
      animation-delay:0s;
    }
    h1 span:nth-child(2){
      animation-delay:0.1s;
    }
    h1 span:nth-child(3){
      animation-delay:0.2s;
    }
    h1 span:nth-child(4){
      animation-delay:0.3s;
    }
    h1 span:nth-child(5){
      animation-delay:0.4s;
    }
    h1 span:nth-child(6){
      animation-delay:0.5s;
    }
    h1 span:nth-child(7){
      animation-delay:0.6s;
    }
    h1 span:nth-child(8){
      animation-delay:0.7s;
    }
    h1 span:nth-child(9){
      animation-delay:0.8s;
    }
    h1 span:nth-child(10){
      animation-delay:0.9s;
    }
    @keyframes san{
      0%,100%{
        color: rgb(255, 255, 255);
        text-shadow: 0 0 5px rgb(1, 231, 247),
        0 0 15px rgb(1, 231, 247),
        0 0 25px rgb(1, 231, 247),
        0 0 50px rgb(1, 231, 247),
        0 0 80px rgb(1, 231, 247),
        0 0 120px rgb(1, 231, 247),
        0 0 160px rgb(1, 231, 247),
        0 0 200px rgb(1, 231, 247),
        0 0 300px rgb(1, 231, 247),
        0 0 400px rgb(1, 231, 247),
        0 0 500px rgb(1, 231, 247);
      }
      20%,80%{
        color: transparent;
        text-shadow: none;
      }

    }
  </style>
</head>
<body>
<h1>
  <span>CO</span>
  <span>NG</span>
  <span>RA</span>
  <span>TU</span>
  <span>LA</span>
  <span>TI</span>
  <span>ON</span>
  <span>！</span>

</h1>
</body>
</html>
